#include <stdio.h>

#define MAX 255

int main() {
    char str1[] = {"hello \0"};
    char str2[] = {"world!\0"};
    char result[MAX];
    int i = 0, j = 0;

    while (str1[i] != '\0') {
        result[j++] = str1[i++];
    }
    i = 0;
    while (str2[i] != '\0') {
        result[j++] = str2[i++];
    }
    result[j] = '\0';
    printf("%s\n", result);
    
    return 0;
}
